How do I get transparent text?

Question

I am trying to make a picture for the cover of my thesis using LaTeX. I have a background picture and I would like to have transparent (math) text on top of it, how do I achieve this? I have tried to install the transparent package, but was not successful.

Answer 1

Here is a non-TikZ solution. We specify the transparency using \transparent{<value>}, where the value is from 0-1. Adjust the values to suit.

\documentclass[12pt]{article}
\usepackage{graphicx}
 \usepackage{color}
 \usepackage{transparent}
 \begin{document}
\includegraphics[width=0.5\textwidth]{./graphics/amato}\par
\vspace*{-3cm}
\hspace*{-1cm} \hbox{%
 \bfseries\Huge
 \color{red}%
 \transparent{0.4}%
 MY THESIS
 }
\end{document}

Answer 2

You could use a tikz node and include the opacity option:

\documentclass{article}
\usepackage{graphicx}

\usepackage{tikz}

\begin{document} 
\begin{tikzpicture}
\node (0,0) {\includegraphics[width=5.0cm]{images/eiffel_tower}};
\node [opacity=0.2] (0,0) {\scalebox{5.0}{\textcolor{green}{$\displaystyle\sum_{n=0}^\infty \frac{1}{x^n}$}}};
\end{tikzpicture}
\end{document}

Answer 3

You may do this with TikZ. In the following solution I put an overlay picture in the title. When the titlepage is printed, it adds the overlay picture. You have to compile this at least twice.

Please note that this solution does put the transparent text on the titlepage, as requested, and should work for any document class. You can control the position of the transparent text by providing a proper coordinate in the \draw command. In the example it's current page.center but it can be anywhere on the page.

\documentclass{book}
\usepackage{tikz}

\makeatletter
\title{How I Got My MSc\overlay@picture}
\author{Me}

\newcommand\overlay@picture{%
\begin{tikzpicture}[overlay,remember picture]
\draw[fill opacity=0.5]
     (current page.center)
     node[scale=10] {$A = B$};
\end{tikzpicture}
}
\makeatother

\begin{document}
\frontmatter
\maketitle
\mainmatter
\ldots
\end{document}